


Expanding Magic: Harry

by daughterofdurinanddestiel



Series: Expanding Magic [2]
Category: Harry Potter - J. K. Rowling
Genre: Anal Sex, BDSM, Bottom Harry, First Time, Gay Sex, Good Severus Snape, Light BDSM, M/M, Oral Sex, Rough Sex, Severus Snape Has a Heart, Severus Snape Lives, Sex, Spanking, Sub Harry, Whipping
Language: English
Status: Completed
Published: 2017-08-29
Updated: 2017-08-29
Packaged: 2018-12-21 08:16:38
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,376
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11940060
Author URL: https://archiveofourown.org/users/daughterofdurinanddestiel/pseuds/daughterofdurinanddestiel
Summary: The war has ended. Harry won, Voldemort died, and Snape lived. Now Harry is seventeen, and he needs to have his expanding magic grounded by an elder. But this isn't how he wants to lose the last vestige of his innocence.





	Expanding Magic: Harry

The war was over. Voldemort was dead. Harry Potter was a hero. And Severus Snape was exonerated for the murder of Albus Dumbledore and association with the Death Eaters. Both men were also given Orders of Merlin: First Class for their war efforts.

And all before Harry’s seventh year of Hogwarts was to begin.

As Harry, Hermione, and Ron walked up to the castle doors on the first night back, they all stopped to stare. The castle had been repaired and was as good as new, under the care of Headmistress McGonagall.

“Am I the only one who feels...off?” Hermione asked, looking on either side of her at her friends.

“Nope, I feel you, mate,” Ron said.

Harry just nodded, remembering the last time he had been on these grounds, he had killed a man and then saved another. After he had killed Voldemort, he had used Nagini’s venom to make an antidote for Snape, after the man had been poisoned. He’d made it using the Half-Blood Prince’s textbook, which had miraculously not burnt up in the Room of Requirement.

And now here he was, schoolbooks in his trunk, as if none of that had ever happened. As if Fred and Remus and Sirius and Colin hadn’t been killed. As if Tonks and George hadn't lost their soulmates. As if he hadn’t lost nearly every vestige of his innocence.

“Well, we faced the Dark Lord: this can't be much worse, right?” Harry said, forcing a smile. And they stepped inside the castle...stepped back into their home.

 

***

 

“Why wasn't I told? I have McGonagall calling me in like...like…” Harry was furious, pacing through the Gryffindor common room. “It’s my first night! Don’t you think I should have been told tomorrow at the earliest?”

Ron was chuckling, but at least Hermione looked sympathetic. It was late, and they were the only three still awake in their House.

“It’s not like you were the only one. I was there, too, and so was almost everyone else in our year,” Ron reminded him.

“But why am I the only one who has to go through with it tomorrow?” Harry asked.

“Because your birthday was all the way back in July,” Hermione pointed out. “Your magic can go out of control at any moment. It’s to save you any more pain.”

Harry plopped down on the sofa next to her. “Who is it, Hermione?”

“Well, I don’t know if the same man will be grounding other men,” Hermione said. “So I’d rather not say. It’s a secret for a reason.”

Harry huffed, concern growing in his mind. When he said almost all his innocence was gone, he meant almost: he was still a virgin, having only come to the realisation that he was gay in sixth year, after kissing Ginny and feeling like he was going to vomit, but looking into Professor Snape’s eyes and feeling a stirring in his groin that he’d never felt before.

And now he was being forced to lose that, too.

 

***

 

The next day, as soon as classes ended, Harry was pulled aside by the Headmistress and told which room in the dungeons to go to.

“Don’t be worried,” she said. “You’re in the safest hands possible, Mr. Potter.”

Harry nodded, not quite believing her, as he descended the staircase to the dungeons, the familiar path soon becoming unfamiliar as he stood across from the Potions lab, facing a door that had never been there until today. At least, not for him.

He hesitated, wondering how bad it could be? After all, he’d faced Voldemort. If he hadn’t blown himself up then, perhaps he wouldn’t need this.

As he was going to turn away, to leave and face the consequences, the door opened on its own, as if it or the person inside the room knew what he was about to do.

_ Damn it, _ he thought, pushing the door open further.

He wasn’t sure if the room always looked like this, but it was blonde-wood paneled, with a large, bed that had silken sheets that matched his emerald green eyes, and a long desk at one end. Seated at the desk was the person who really gave him pause.

“About to run away, were you?” Severus Snape asked, smirking. “The brave Saviour of the Wizarding World was about to run away with his tail between his legs. Shall I tell the  _ Prophet _ ? Call up Ms. Skeeter?”

Harry’s face flamed. “After all we’ve been through, you’re still a bastard.”

“Did you honestly expect anything else from me, Potter?” the professor asked. “Sit. Allow me to explain things to you.”

“I think I know well enough what’s to be done,” Harry ground out, wishing that the man wasn’t so damned sexy as he sat there, reclining in the chair in such a relaxed manner. Harry wanted to scramble into his lap and snog him senseless at the same time he wanted to run and not come back.

“Oh, so you know the spell we must recite?” Snape asked, arching an eyebrow.

“No,” Harry muttered, reluctantly sitting across the desk from Snape.

“Very well, then. You were quite fortunate that Voldemort attacked you on your seventeenth birthday, because that is the day that your magic begins to grow and expand. Normally, you would be grounded by an experienced elder on your birthday, but those children born during the summer holiday usually have to wait. In your case, we were fortunate that you were born in July. It allowed you to have enough magic to defeat the Dark Lord.

“However, the longer the magic remains expanded within you without the grounding spell, the more danger you pose not only to yourself, but to everyone around you.” Snape passed Harry a piece of paper with a spell written on it.

“Why sex?” Harry asked. “Why does it have to be sex?”

Snape sighed. “Because it is the most intimate and personal act that can be had...aside from murder. And while you may still wish to murder me at times, I assure you it would take more than  _ Expelliarmus  _ to defeat me.”

“You taught me that spell, in case you’ve forgotten,” Harry snapped.

“It is quite difficult to forget anything about you, Mr. Potter. You’ve been a thorn in my side for sixteen bloody years.” He stood up. “At the very least you grew up to be avery handsome thorn. Makes this much easier on me.”

Harry felt a blush rise up into his cheeks at the flippant compliment coming from a man who had been his enemy just a few months ago.

“Two warnings: this must be done without Muggle forms of protection--rest assured I am disease free, unless you count the Dark Mark. And the harder, the better. Any objections?” Snape stared down at Harry, dark eyes burning into him.

“I--well, you see…” Suddenly, Harry lost the ability to speak.

“Spit it out, Potter. We might have all night but I’d much rather spend it shagging than standing here watching you stammer,” Snape said.

Hating to admit it but knowing he had no choice, Harry muttered, “I’m a virgin.”

Instead of mocking him as he’d thought he would, Snape smirked. “You thought I didn’t know?” He chuckled. “Oh Potter, it gives me great pleasure to be the one who deflowers the Saviour of the Wizarding World.” He walked around the desk and ran his hand down over the bulge in Harry’s trousers. “And it seems to me you’d like that.”

“Yes, sir,” Harry said, his voice but a whisper.

Snape circled around Harry, unclasping his Gryffindor robe from behind and letting it fall to the floor; the tie following soon after. Long, nimble fingers undid the buttons on his school shirt, brushing against his heated skin with every one undone.

Harry sucked in a breath as Snape just brushed against one of his nipples. Eventually he was freed of his shirt, the cool air hitting bare flesh. From behind, he felt Snape’s clothed body press against him, hands roving all over his exposed skin.

“Do you know anything about this room?” Snape asked.

“No,” Harry said, wondering why he chose now to bring up the room when Harry could feel Snape’s clothed erection pressing against his backside.

“It changes depending on what each student wants. The bedsheets match your favourite or eye colour, depending. For you it chose your damned, beautiful eyes. The desk isn’t always here, either. And I know why there’s a desk matching the one in my office in this room.” Harry could hear the smile in that sentence. “Take off your belt and get on your knees.”

Harry did as he was asked, holding the belt in one hand as he knelt before his professor.

“I swear, Potter, there are days you’re so beautiful it fucking hurts to look at you,” he said, placing his hand on Harry’s chin. Clearing his throat he continued, “Now, ever since you set foot in this place, you’ve been above the rules. Now it is time for your discipline.” He tapped Harry’s cheek. “Open up, Potter. And keep your hands behind your back at all times.”

Harry did as he was told, watching in apprehension as Snape removed his frock coat and untucked his white shirt. He unbuttoned his trousers, freeing an impressive cock that made Harry’s own appendage twitch interestedly. He had no idea how that was going to fit inside him, but he didn’t need to worry about it right then, because it was going in another hole.

Harry had sucked guys off before, had just been too chicken to go any further, but he liked to think he was good at it and could finally impress Snape.

“Keep your eyes on me, Potter,” Snape ordered, giving his cock a few quick strokes before bringing the tip to Harry’s mouth.

Harry closed his lips around the head, tasting the salty precome that had already been gathering there. Snape hissed and Harry started to suck as though his professor was a lollipop from Honeyduke’s.

“Mmm. It seems you’re not completely innocent, are you?” Snape asked as Harry’s tongue traced the vein on the underside of his cock.

He pushed a few inches inside, and Harry loved the heavy feeling of the cock in his mouth. This was nothing like quickly sucking off Oliver Wood in the locker room, or his one fumble with Malfoy in the Room of Requirement. Snape knew what he was doing and he knew what he wanted from Harry.

Snape went to push in further, and automatically Harry reached to grab the base, forgetting his earlier instructions.

Snape slapped his hand away, grabbing the thin wrist tightly in his large hand. “No hands, Potter. Stay still and keep your fucking mouth open.”

Harry did as he was asked, feeling apprehensive as more of Snape went down his throat, causing his gag reflex to act up. He choked around the intrusion, tears coming to his eyes.

“Come on, Potter. You always have a smart aleck thing to say. Nothing to say now?” Snape smirked down at him, and Harry was torn between being turned on and being humiliated.

He stayed as still as possible as Snape began to fuck his throat in earnest, his cock pulling nearly all the way out before slamming back down his windpipe. Harry tried his best to relax, to not choke, but his balls were constricting in his trousers from the rough treatment. All he wanted was relief.

He’d been used his entire life, by his aunt and uncle, by Dumbledore, by Voldemort, and even to some extent by his friends. But never had he thought he’d enjoy being used, especially not like this.

He hummed in his throat as Snape held his cock there for a moment, causing vibrations to hit his professor.

Snape pulled out of his mouth, groaning from his own impending release.

Harry sighed with relief, breathing free air at last.

“Hand me the belt, Potter.”

Harry did so, noticing that his hand was shaking. He needed relief, and he needed it badly.

Snape put his hand in his hair and hauled him to stand, spinning him around and spelling away his trousers and pants. The cold air hit Harry’s hot cock and gave some relief and he sighed. Snape’s hand ghosted over his arse, fingering the crack and then squeezing each rounded globe in turn.

“I’ve waited years for this moment. And I believe you have, too, whether you know it or not.” His warm hand pressed the centre of Harry’s back, forcing him to bend over the desk, arse in the air.

“Count, Potter. Miss a stroke and I start over again.”

What? Harry wasn’t entirely sure what was happening until he heard a slapping sound and felt a stinging in his arse. Snape was whipping him with his belt.

Harry had been whipped many times as a child by his uncle, but never once did he find it arousing.

“One,” Harry said.

“Good boy.” Snape whipped him again, in a different spot.

“Two.”

He was hit again.

“Three.”

By the fourth hit, Harry knew that Snape wasn’t drawing blood, not like his uncle had. This was punishment, yes, but it wasn’t meant to be endured...it was meant to be enjoyed. His cock was harder than ever, pressing against his stomach and begging to be relieved of this horrible tension. At the same time, he never wanted this pain to end.

“Fucking painslut, Potter. Or just a slut, period. Well...after this you will be, in any case,” he said, continuing to assault the flesh of Harry’s arse. “Tell me, do you like it? Do you deserve this?”

Harry took a breath through the pain and said, “Yes, sir. I like it and I deserve it. ...For all the times I stole from you, talked back to you...and for every time I came in my bed, thinking about you doing just this.”

Snape growled low in his throat, hitting Harry again, for the fifteenth time. By the time he hit twenty, Harry’s arse was on fire and he wouldn’t be able to sit for a week at this rate, and his cock was going to be disabled if he didn’t come soon.

The belt was thrown to the floor, and Harry risked a glance at Snape.

The man’s cheeks had bright spots of colour, and his eyes were sparkling with mischief. But it was the dark smile he had on his lips that nearly made Harry come right then and there. It promised sex and pain and perfection. It promised everything Harry had never known he wanted.

“Professor, sir, please,” Harry begged.

Snape shoved Harry hard into the desk. “How I love to hear you beg from those pretty pink lips. Do not worry: when I’m done with you there won’t be a drop of come left except for what I’ve shot into you.”

Harry moaned and then hissed in pain as Snape grabbed his already abused arse cheeks and spread them apart.

“ _ Praelino _ ,” Snape said, and Harry felt a slick finger press into his arsehole. Snape said the spell again and Harry felt warmth in his hole. He’d prepared himself before, but never had it felt so acutely erotic.

“That’s it, spread your legs like a good little slut,” Snape purred as he twirled his finger inside Harry.

Harry held his breath as he was breached by two, and then three lubricated fingers. It felt so good, so different from when he did it himself. Snape was thrusting his long fingers in and out of his arse, twisting them just so and Harry saw stars.

“You like that, don't you?” Snape said, biting Harry’s ear. “See, grounding your magic isn’t so bad, is it?”

“Ugh...stop talking and fuck me already,” Harry said, pushing his arse back on Snape’s fingers.

Snape spanked him, this time with his bare hand. “You are not in charge here, Potter.” The fingers slipped out of his arse and he tensed when he felt something much larger than fingers press against his loosened hole. “And you really should be careful what you wish for.”

Harry gasped as the head breached his arse, gripping the table for dear life.

“Easy, Potter,” Snape said, his voice low and soothing. “This is going to hurt. But I promise I will do what I can to ease the burn.” A warm hand settled on Harry’s lower back as Snape slowly pushed himself inside.

Harry gasped at the new intrusion, but it wasn’t as painful as he’d been expecting. Surprisingly, Snape was still protecting him, even now.

The professor pressed harder, and in a few moments Harry was so full, completely filled in a way he had never imagined.

“Are you okay?” Snape asked, still rubbing his back lightly.

“Yes, sir,” Harry replied. “But please, if you don’t move soon I may die.”

Snape chuckled, his lips close to Harry’s ear. “As you wish, Mr. Potter.” Snape rolled his hips and pressed even harder into Harry, and the boy yelped in surprise. “You might want to get a good grip on the table. And don’t even think of touching yourself. Tonight, that belongs to me and me alone.”

Harry scrambled to grip the desk again, his cock throbbing at the words and tone Snape used. The professor pulled almost completely out of Harry before pushing back in, rocking Harry into the desk. He’d be bruised the next day, but that was fine with him as long as Snape never stopped doing  _ that _ .

Snape soon found a rhythm he liked, and Harry was left at his mercy as his arse was repeatedly pounded from behind. His cock was leaking, and his knees felt weak with the force of the thrusts, Snape’s long cock claiming him in a way none ever had before.

Snape pulled out completely and Harry couldn’t help but whine. His whinging resulted in a few sharp slaps to his already bruised arse cheeks. He yanked Harry’s hips back, forcing him to lay his entire upper body down on the desk, scattering pens and pieces of parchment all over the floor.

In one perfect movement, Snape was back inside of him, the head of his cock hitting Harry’s prostate with every thrust.

“Fuck!” Harry cried when he felt it for the first time, very nearly seeing stars. “I’m not gonna last much longer if you keep doing that.”

Again that dark laugh hit his ears. “Oh, Potter, I don’t expect you to.” More thrusts, so hard the entire desk was shaking. Snape was starting to lose his rhythm a little and he said, “Now, Potter. Come.Come for me.” He wrapped his large hand around Harry’s cock and pulled.

Harry didn’t need any more encouragement as he spilled himself all over Snape’s hand. A few more erratic thrusts later, he felt himself being filled with warm liquid. Snape had filled him with his seed, claimed him utterly and completely.

“The spell, Potter.”

Harry had nearly forgotten why he was there! That damned spell. He uttered it quickly, and Snape said his part right after.

Harry felt the magic building within him, an invisible connection between the two men. He was breathing hard, nearly panting, and his body felt weak yet energised at the same time.

He felt Snape gingerly pull out of him, and he knew he’d be sore and bruised for days, but he didn’t mind.

“Get dressed, Potter.”

Harry turned to see Snape was already buttoning his trousers and looking for his overcoat. He waved a callous hand in Harry’s direction, and he was cleaned up from the mess he and the professor had made.

He now felt acutely embarrassed and shy, standing stark naked before his clothed professor.

He flashed him a smile as he went to gather his clothes and Snape arched an eyebrow.

“Think we could do this again sometimes?” Harry asked.

“Potter, I do not make it a habit of shagging my students,” Snape replied. “While you will always be one of my...most memorable lessons. Now get out.”

Harry winked cheekily, now fully dressed. “Looks like we have yet another thing in common: we’ll both never forget today.”

**Author's Note:**

> Thanks for reading! Don't forget to check out Hermione/Severus in part one!  
> Future characters whose magic Snape will be grounding:  
> Draco  
> Harry (again, you'll see)  
> Pansy Parkinson  
> Ginny (it was a request)  
> Tonks (flashback)  
> I'm open to suggestions if you all have anyone else you want to see. (Please...not Ron.)


End file.
